Mold for making steel castings.



No. 856,251. PATENTED JUNE ll, 1907. C. HAGSTROM.

MOLD POR MAKING STEEL CASTINGS.

APPLICATION FILED AUG. 28, 11906.

UNITED STATES PATENT OFFICE.

CARL HAGSTROM, CF LYNN, MASSACHUSETTS.

MOLD FOR MAKINGSTEEL CASTINGS.

. Specification of Letters Patent.

Patented June 11, 1,907.

Application led August 28, 1906. Serial N- 332,381.

specification.

My invention relates to the making of castings, being especially applicable to the production of large steel castings in sand or .similar molds of finely divided refractory material.

Ordinarily in metal founding, the contact surface `fori the molten metal is produced upon the interior of the matrix by tamping the sandin the flask firmly about a pattern, which is then withdrawn. It is found, however, thatl the intense heat of the metal introduced burns or so acts upon the surface of the sand that portions become detached, and are embedded in the casting, making itdiificult to machine. y

The principal ob'ect of my invention is to produce a casting free from this defect, thus greatly increasing the ease and economy-of working.

Of the accompanying drawings forming apart of this specicatiom-Figure 1 shows in vertical section the upper or cope portion of a mold arranged in accordance with my invention. `Fig. 2 shows a top plan view of the same.

This invention may be carried out by various forms of molds, and by protecting their surfaces wholly or partially, but it is particularly usefulin connection with large castings having angular or other portions from which the sand is especially liable to become displaced, or what may be called vdanger points.7 The general application of'theinvention being understood, it will be here described by reference to one embodiment in which only these danger points are to be protected.

In the drawings, 10 designates the cope of an ordinary two-part flask, in which the sand matrix l1 has been tamped about` a att-ern to produce its half of the depression rnishing the mold, a passa e or gate 12 being formed through the san for the introduction of the molten metal. The mold is shown as having a corner or angularl portion 13 at 'the meeting of two surfaces, and this might be loosened by the metal when our'ed, as has been 'previously described. o prevent this and to secure a simple and perfect casting, 'I t.

place over this portion ofthe'mold surface,

causing it -to substantially conform thereto,

a lining 14 of some material which will be meltedby the heat of the substance 'to be cast. This lining is preferably of very thin sheet metal, say 1/64 in thickness, and of any suitable surface dimensions and being of the same character as that forming the casting. The lining sheets may be secured in place by nails 1.5, driven through the corners or wherever is necessary into the 'l densely packed sand. As the metal lflows through the gate, the sand is protected by the lining, so that the surface sand is not burned and separated from the remainder of the matrix. As soon as the molten metal fairly comes into contact with the lining, the latter liquefies and becomes a portion of the castin bringin the metal against the surface o thev san but as the former is now somewhat chilled, all danger of loosening the sand is passed. Thus itwill be seen that the casting will be true to all the mold surfaces, yet be'entirely free from'sand.

1. A mold for casting, which comprises a sand matrix,and a lining consisting of a solid which will be liquefied by the heat of the substance cast..

2. A mold for metal founding, comprising a matrix of finely divided refractory material, and a'lining consisting of a metal which will be liquefied by the heatof the metal cast.

3. A mold for metal founding, comprising a matrix of finely divided refractory material, a lining consisting of sheet metal gen erally conforming to t e surface of the ma trix, and means for securing the lining to the matrix, said lining bein composed of` a metal which will be liquefied bythe heat of the metal cast.

4. A mold for metal founding, comprising a matrix of sand, a lining of sheet metal generally conforming to the surface of the ma` trix, and securing means passing through the sheet metal into the sand, said lining bein com osed of a metal which will be liquefied by t e heat of the metal cast.

l In testimony whereof I have affixed my signature, in presence of two witnesses.

CARI) HAGSTROM.

IOC 

